Dock levelers comprise, generally, hinged ramp structures which are disposed at vehicle loading docks to provide a ramp extending between a vehicle loadbed and the loading dock to facilitate movement of cargo between the dock and the vehicle and to overcome any difference in elevation between the floor of the vehicle loadbed and the dock. Several dock leveler mechanisms have been developed which provide for movement of the dock leveler from an at rest or stored position to a working position connected to a vehicle loadbed, regardless of the loadbed height relative to the loading dock and the leveler structure, at least within an expected range of heights.
Prior art actuating mechanisms for dock leveler ramps and extension lip members are somewhat complex. Moreover, due to the change in height of the vehicle loadbed with respect to the dock during loading and unloading operations, dock leveler actuating mechanisms are subject to rapid wear and unwanted damage as a result of this type of movement.
In spite of the prior development efforts regarding dock leveler mechanisms, there has been a strong felt need to provide an improved actuating mechanism for the hinged ramp type dock leveler. A need has also persisted for a suitable mechanism to minimize rapid movement of the dock leveler, particularly in a downward direction, if the vehicle being loaded is suddenly pulled away from the loading dock. Still further, there has also been a desire to provide improvements in dock leveler mechanisms which provide for extending the hinged lip at the forward edge of the main ramp to a working position, for latching the lip in a working position and for supporting the ramp in a stored position.
It is to these ends that the present invention has been developed.